Water-tube boiler with superheaters



LVZZM'YE July 23, 1929., B. BROIDCJ WATER TUBE BOILER WITH SUPERHEATERSFiled Dec. 29, 1925 6 Sheets-Sheet IN VEN TOR. jEAA/fl/vlzx .BEO ADO ATTORNEY.

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WATER TUBE BOILER WITH SUPERHEATERS Filed Dec. 29, 1925 6 Shee'bsShee1;3

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Jufiy Li; H929. B. BROIDQ WATER TUBE BOILER WITH SUPERHEATERS Filed Dec.29, 1925 6 Sheets-Sheet 4 00 O0 00 O0 00 00 O0 00 00 OO 00 0O 00 00 00 IN VEN TOR. ,.3/\//4A4/A/ .520 ADO A TTORNE Y.

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WATER TUBE BOILER WITH SUPERHEATERSV Filed Dec. 29, 1925 6 Sheets-Sheet5 .zizM/nwm/jao/ao INVENTOR A TTORNEY.

m. 0 R B B WATER TUBE BOILER WITH SUPERHEATERS HIM DW- 29, 1925 6awaits-Sheet 6 O O O 0 Q 0 O EEA/J/WWIMflE-Q/DQ INVENTOR.

A T TORNE Y.

Patented July 23, 1929.

UNITED STATES PATENT OFFICE.

BENJAMIN BB-OIDO, or New YORK, N. Y'.', nss renon TO THE surnnnnnrnnCOMPANY,

- on NEW YORK, N. Y.

WATER-TUBE BOILER WITH SUPERHEATERS.

Application filed December as, 1925. Serial No. 78,133.

My invention relates to water tube boilers equipped with superheatersand has for its principal purpose the provision of an arrangementwhereby the superheater units or elements shall be near enough to thefurnace to deliver steam superheated to the hi htemperatures demandedto-day and yet s all be properly protected from the intense furnacetemperatures and whereby at the same time the gases shall be welldistributed and all of the units shall receive gases of substantiallythe same temperature. Other objects of the invention-will appear fromthe following description:

The invention is disclosed in the drawings filed herewith in which Fig.'1 is a longitudinal section'of a water tube boiler arranged accordingto my invention; Fig. 2 is a transverse section on line 22 of Fig. '1;Fig. 3 is a section similar to that of Fig. 1 illustrating a variationFig. 4 is a section on line 4-4 of Fig. 3; Fig. 5 is a longitudinalsection of a boiler of a. different type illustrating my arrangementapplied to it, and Fig. 6 is a section on line 66 of Fig. 5 looking inthe direction of the arrows.

I shall first refer to the form of my inv vention shown in Figs. 1 and2.

e boiler is of the usual form and may be briefly described as follows Afront header 1 is connected to a rear header 2 by a bank of water tubes3-3. The headers 1 and 2 may be either unitary or sectional. The frontheader 1 is connected to a steam and water drum 4 by means of connectingpipes 5; and the rear header 2 is connected to the same drum 4 by meansof the tubes 6.

Below the headers 1 and 2 there are additional headers 7 and 8respectively which may also be either unitar or sectional and which areconnected to eac other by means of the water tubes 9. Header 7 isconnected with header 1 by means of the nipples 10, while header 8 isjoined to header 2 by nipples 11.

Steam is taken off fromdrum 4 by means of the pipe 12 and led by it tothe inlet header 13 of the superheater. This superheater comprises aseries of tubular superheater elements or units 15, one end of each ofwhich is connected to the header 13, the other being connected to theoutlet header 14.

The entire boiler structure thus briefly described is enclosed in ahousing A. Baffies 16 direct the gases from the furnace 17 on their wayto the stack connection 18. In the form of furnace shown pulverized fuel,is to be burned, one ofthe burners being shown at 19.

The arrangement so far described is not novel. It has become commonpractice re? cently to install so called water screens in boilers, asillustrated in the present case in connection with the two side Walls ofthe setting. The water screens shown are made of upper and lower headers20-20 and 21-. 21 respectively connected by water tubes 22- 22. In thepresentinstance these tubes 22 are bifurcated. They form practically,continuous water cooled surfaces thoroughly protecting the side Walls.'The lower head ers 2121 are supplied with water by means of theconnecting pipes 23-23, which communicate with the lower header 7 bymeans of the nipples 24. The upper headers 20-20 are connected to thesteam and water drum 4 by means of the pipes 2525 and nipples 26.Obviously some other connections may be used for circulating waterthrough these water screens, and the screens themselves may vary inconstruction from that shown.

Water screens such as described will result in a somewhat loweredtemperature of the gases leaving the furnace. In order to ob- 'tainthedesired degree of superheat from the superheater it therefore becomesnecessary to place the superheater nearer the fur nace, that is, tointerpose fewer water tubes between the superheater and the furnace thanwhere water screens are not used. lVhen this is done, however, there isdanger that the super-heater elements toward the center of the furnacewhere the effect of the-water screen is not so pronounced may be injuredby the intense heat. By means'of my arrangement presently to bedescribed it becomes possible to allow for the cooling experienced bythe gases due to the presence of the water screen and yet properly toprotect the superheater.

This effect is obtained by arranging the water tubes which areinterposed between the superheater and the furnace in a manner clearlyshown in Fig. 2. In this figure there are shown two rows of water tubesin the Lower bank extending clear to the-side wall. There are additionalrows below these two but these additional rows terminate at pointsprogressively nearer the center of the furnace, the result being thatgases Which strike52 and 53. The details of this boiler need thesuperheater near the water cooled side walls coine into "contact withfewer of the boiler tubes than do the gases nearer the center of thefurnace. The inequalities in gas temperaturescaused by the water screensare thus equalized and the temperature of the gases striking thesuperheater is substantially constant throughout the width. of theboiler.

The precise number of tubes interposed near the side walls and the rateat which this number of rows is increased toward the center is of coursea matter whichmay vary from case to case depending upon the furnacetemperatures, the degree of superheat desired, the size of thesuperheater, etc. The essential point in the invention is that overthose areas where the'gases are affected by the presence of the waterscreen the interposed surface is cut down by a corresponding amount.

The side walls may also be cooled in some other way than through thepresence of a water screen. They may for example be used to preheat air,such preheating resulting in a cooling of the walls and a consequentincreased cooling effect on the gases near the walls. This isillustrated in Figs. 3 and 4. The boiler arrangement is heresubstantially like that of the form first described. Air for combustionis preheated in the hollow side walls entering at 30-30, flowing throughthe channels 31-31, and being delivered into the furnace through theopenings 3232.

The air-cooled side walls will as stated cool these gases coming intoproximity to them and this is compensated here in the same way as in thefirst case, that is, by decreasing the number of the tubes towardthe-side walls as compared with their number toward the center.

Even where the side walls have no water screens or air ducts, the mereradiation of the side walls results of itself in a lowering of thetemperature of the gases in their proximity as compared with thetemperature through the body of the furnace, and my inventioncontemplates a similar compensation for this loss in temperature in suchcases bydecreasing the number of water tubes below the superheateradjacent to the side walls, and as far as the cooling effect extends.

.In Figs. 5 and 6 I illustrate my invention as applied to a boiler withwhat are commonly called upright water tubes. The boiler in this casecomprises three banks of tubes 40, 41 and 42, which connect a lower drum43 with the two upper drums 44 and 45. A third upper druin 46 isconnected to'the drums 44 and 45 by means of tubes 47 and 48. Thisboiler structure is enclosed in an appropriate housing, and the gasesfrom the furnace 49 are directed on their way to the stack connection 50by means of the ballles not be further described as they do not enterinto the invention. Boilers of a somewhat difi'erent construction allowequally well of the application of my invention.

The superheater-in this case although it might also be placed in an openspace between banks of tubes is for illustrative purposes shown asplaced into the spaces between the tubes of the front bank 42, theseveral tube lengths 54 of the superheater running parallel to the watertubes 42. The ends of the superheater units-are connected to the twoheaders 55 and 56. i A water screen 57 similar in construction to theone described in connection with Figs. 1 and 2 protects each of the sidewalls. This water screen is connected to the boiler circu-- lation bymeans of the connections 58 and 59. An inspection of Fig. 6 will showhowmy invention works out in connection with a boiler of this type.Additional water tubes 60 are interposed between the space through whichthe superheater is distributed and the furnace space. Therow next to thesuperheater extends clear to the side walls at each side, the second rowterminating short of each side wall and the third row terminating oneach side at a point more remote yet from the side wall. While there areshown only threerows of such water tubes it is of course within thescope of my invention that more may be used. This will depend on circumstances in each case.

What I claim is 1. In apparatus of the class described, the combinationof a. boiler setting comprising a wall cooling the hot'gases in thefurnace coming into proximity to it, a superheater distributedthrough aspace from the wall in- Ward, heat abstracting means between the furnaceand the superheater so distributed that there is less of it adjacent tothe wall than at points remote from the wall.

2. In a horizontal water tube boiler, the combination of a boilersetting comprising two lateral furnace walls, means cooling said lateralwalls, a bank of horizontal 'water tubes extending from the front to theback of the setting and filling the space from side to side, asuperheater beneath the bank comprising superheating elementsdistributed from one side of the setting to the other, a row of watertubes below the superheater extending from front to back and distributedfrom one side to the other, and additional rows of water tubes belowsaid last named row extending from front to back and distributed overspaces terminating on each side at points progressively farther fromthe-wall.

3. In a horizontal water tube boiler, the combination of a boilersetting comprising two lateral furnace walls, water screens adjacent tosaid lateral furnace walls, a bank of horizontal water tubes extendingfrom the front to the back of the setting and filling the space fromside to side, a superheater beneath the bank comprising superheatingelements distributed from one side of the setting to the other, a row ofwater tubes below the superheater extending from front to back anddistributed from one side to the other, and additional rows of watertubes below said last named row extending from front to back anddistributed over spaces terminating on each side at points wall.

4. In apparatus of the class described, the combination of a boilersetting comprising a wall cooling the hot gases in the furnace cominginto proximity to it, a superheater distributed through a space from thewall inward, water-cooled heat abstracting means between the furnace andthe superheater so distributed that there is progressively more of it atpoints progressively more remote from the wall.

5. In apparatus of the class described, the

combination of a boiler setting comprising two opposite walls coolingthe hot gases in the furnace coming into proximity to them, asuperheater distributed across the space between the walls, water tubesarranged between the' furnace and the superheater their numberincreasing progressively toward the center.

progressively farther from the 6. In a water tube boileiythe combinationof a boiler setting comprising two side walls cooling the hot gases inthe furnace coming into proximity to them, a bank of water tubesdistributed from one side wall to the other, a. superheater comprisingsuperheatin elements likewise distributedfrom one si e wall to the otherand arranged nearer the furnace than said water tubes, and a pluralityof water tubes arranged between the furnace and the superheater in sucha manner that the number of such water tubes with which the furnacegases come into contact before reaching the superheater increasesprogressively with the distance from the side walls.

7. In a water tube boiler, the combination of a boiler settingcomprising two side walls cooling the gases in the furnace coming intoproximity to them, a superheater comprising tubular superheater elementsdistributed from one side wall to the other, and boiler tubes likewisedistributed from one side wall to the other, the smaller portion of saidwater tubes being arranged between the furnace and the superheater andbeing so distributed that the number with which the furnace gases comeinto contact before reaching the superheater increases progressivelywith the distance from the side walls.

A BENJAMIN BROIDO.

